So I got an 08 600RR last month. I've been riding a VFR for like 15years (not the same one) and the VFR is all I know. Then I get this CBR and WOW, its a kick in the pants. I love it. Then I started looking around the bike and I noticed this servo and cables under the tail that go to the exhaust pipe. It looks like some kind of valve for the exhaust. Anyone know what this thing is and what it does? Can/ should I disable it? Is it for smog and noise or for back pressure and torque? I have no idea. Can anyone enlighten me? Thanks.

Where exactly do you see the cables connected to the exhaust? I was intrigued by your question...........so I went down to the garage where my roommates 07 600RR lies (which is the same as the 08 models), and couldn't find any cables connected to the actual exhaust itself. The only wires I noticed are the ones that run right along the exhaust pipe to run the turnsignals/brake/plate lights. There was another one towards the base of the muffler that is connected to a black box and runs to behind the motor. But none of these cables/wires are actually "connected" to the exhaust.

just like the 1000rr the cables can be removed with no adverse affect on performance.

some people will say that it will cause a decrease in low end torque because of reduced backpressure or some garbage like that but i posted a dyno sheet months ago showing cables before and after removal and the graphs were within 1hp of each other all the way through the curve

__________________
street-2006 1KRR,
track-07 600RR

yes, i guess maybe i can be a jerk, but i am tired of reading the same questions and hearing the same would be experts give out wrong info.

The only way to disable the exhaust valve is to disconnect the cables. I would only do this if you plan to replace the exhaust itself, otherwise it might make your performance worse. Don't remove the servo itself or the FI light will remain lit on your gauges. The only way to permanently remove the ex valve is to replace the ECU with the HRC model.

so many others but they all pretty much say the same thing.
in fact the only sites i found where they say that any backpressure is good is where the pipe is too large and allows the gas velocity to slow down, or just some guys opinion with no scientific evidence

__________________
street-2006 1KRR,
track-07 600RR

yes, i guess maybe i can be a jerk, but i am tired of reading the same questions and hearing the same would be experts give out wrong info.

so many others but they all pretty much say the same thing.
in fact the only sites i found where they say that any backpressure is good is where the pipe is too large and allows the gas velocity to slow down, or just some guys opinion with no scientific evidence

So how about that dyno sheet then? can you explain how the exhuast manifold valve works then? When is it open? When is it closed? is it open or closed when power is applied? how does this benefit the motorcycle? Federal sound level emissions remained unchained for the 2007 model year run so it wasn't because honda was trying to 'fly under the radar' for noise emissions. there was a reason.

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